Motor-drill.



G. F. & L. E. HOCHRIEM.

MOTOR DRILL.

'APPucATloN FILED JULY 26, 1915.

f ,1,214,68Q- Patented Feb. 6,1911,

2 SHEETS-SHEET l.

G. F. f L. E. HOCHRIEM.

MOTOR DRILL. lAPPucA'TxoN FILED JULY 26.1915.

Patented Feb. 6, 1917.

2 SHEETS-SHEET 2.

Waag@ l Larnaca.

GUSTAV F. HOCHRIEM AND LUDWIG E. HOCHRIEM, DF CHICAGO, ILLINOIS.

MOTOR-DRILL.

Speoication of Letters Patent.

rammed irene, reir.

Y Application filed July 26, 1915. Seria1No.42,089.

To all 'whom it may concern:

Be it known that we,`GUs'rAv F. Hooli- RIEM, a citizen of the United States, and

E. Hooi-.ruime a subject of the Emperor of Germany, residing at 4426 Sheridan road, in the city of Chicago, county vof Cook, and` State of Illinois, have invented certain new and useful Improvements in Motorl Drills,'of which the following is a specification.

Our invention relates to improvements in motor'drills and more particularly to safety y devices therefor.

K tric circuit and thereby automatically stop 'X-X in said Fig. 7.

l The objects of our invention are to so arrange a safety mechanism that in the event of an abnormal strain being placed upon the drill or the drill becoming stuck or otherwise stopped, the motor shall be automatif cally disengaged therefrom thereby obviat- .ing any possibility of the fuse blowing out, to connection with the motor employ means in disengaging device for breaking the elecping the motor and to provide separate manually controlled means for starting or stopping tlie motor. These and other objects we accomplish as hereinafter described in the following specification and as particularly pointed out in the appended claims, reference being had to the accompanyin drawings i'n which an embodiment of our invention is shown.

In the drawings: Figure 1, represents a side elevation of our improved motor drill. FigJQ is an enlarged fragmentary central vertical section to illustrate the circuit breaking mechanism7 taken on line 2--2 Fig. 7, and looking` in the direction of the arrows Fig. 3, is a transverse section taken on line 3-3 Fig. 6 and looking in the direction of the arrows z-e in said Fig. 6. Fig. 4, is a fragmentary view to illustrate the clutch members in their disengaged position. Fig. 5, is an enlarged fragmentary longitudinal section taken through the drill on line 5-5` Fig. 7 and looking in the direction of the arrows W-'VV Fig. 6. v Fig. 6, is an enlarged central longitudinal section through a fragment of the intermediate portion of the drill stem. Fig. 7, is an enlarged transverse section through the upper inclosing casing of the drill to` show the interior construction thereof in top plan.

In referring to the adaptation or embodi-l ment of our improvement shown in the accompanying drawings in detail, like numerals designate corresponding parts.

We have illustrated our improvement as attached to a motor drill of the electric type in the accompanying drawings, but desire to state that it may be fitted to otherstyles of drills and as will be hereinafter described `is adapted to be employed in connection with various other tools and machines.

As shown the electric motor which may be `yof any of the well .known forms is arranged within a housing 1, from the top of which a slotted handle 2, extends that is 'adapted to be grasped by one hand of the operator. A

lateral handle 3, also extends from the side of the housing which can be held in the other hand of the operator. An end `plate 4, is bolted or otherwise secured to the lower portion of the housing from whichv a tubularV extension 5, depends. Within the extension 5, is rotatably mounted a shaft 6, which carries a gear wheel 7, at' its upper extremity that meshes with a similar gear wheel 8 on the driving shaft 9, of the motor as shown in Fig. 2. extremity 10, which fits in the vupper portion of a knurled and tubular block 11.'

lVhat is lperhaps our invention has reference to a safety clutch mechanism which is interposed between the motor and the drill or chuck and is self-re'- leasing to enable the drill to disengage itself automatically, when subjected to a severe or abnormal strain or when stuck, from the rotating power. This prevents breakage of the drill and relieves any `undue or heavy torsional strain on the driving shaft and operating mechanism.

The clutch mechanism is interposed between the block 11, and the chuck in which the drill is supported and preferably comprises' a lower clutch member, an upper provided with substantially \.'shaped clutch The shaft 6 has a reduced lower the principal feature of lugs 13, andv an uppervtubular portion 14, which is arranged to telescope or slide within the recess of a knurled sleeve 15. The upper end of the op'ening in the sleeve isreduced in' size and a shaft extension 16, which has its upperl end firmly fitted in the lowerportion of' the opening in the block 11, passes through saidi sleeve and the upper clutch'member, and is fastened by pins 17, at its lower extremity in a top recess in the lower clutch member 18, as shown in Fig. 5.

The openings or recesses in the upper clutch member and the sleeve 15, together form an interior chamber 19, in which a clutch tensioning spring 20 is arranged. We preferably make the lower' end 21 of the lower clutch member tapering so that it can.

be snugly wedged in a tapering recess in the top of a drill chuck, 22 as shown in both Figs. 1 and 5,v and thus secure the clutch member and drill chuck together. The lower clutch member is provided with substantially V-shapedQtop clutch grooves 23, in which the clutch lugs 13 of the upper clutch member fit and seat when the clutch members are in clutching position.

The outer surface of la ortion vof the upper clutch member is pre erably knurled as shown at 24 in Fig.4 1, and is `also provided with anangular slot 25, one part of which extends transversely and the other part longitudinally of the shaft Vextension 16. A pin 26 which extends laterally outward from the shaft extension 16,' projects through the angular slot 25, as shown in Figs. 1 and 4. The purpose of the pin and -slot is to limit the transverse turning and longi tudinal sliding movement of the clutch member on4 theshaft extevsion. The clutch is so arranged that whe van abnormal strain is put upon the drill which is sufficient to overcome the frictional engagement of the vtapering surfaces of the clutch members and the tension of the.4 spring 20, the upper clutch member raises and disengages itself from the lower member thereby permitting the motor to run idle. This operation is automatic and provides a safety means to prevent the drill proper being broken.

In addition to the safety automatically disengaging clutch mechanismheretofore described, we may provide a means for stopping the motor and if the motor be of the electric type of breaking the electric circuit f to obviate any possibility of the fuse burning out. The preferable form of the means we employ for this purpose is automatically operated from the upper clutch member and comprises a rod 27, which passes centrally through the shaft 6, the block 11, and into a deep central recess in the shaft extension 16, as shown in Fig.,5; a walking beam lever 28, fulcrumed or pivoted at an intermediate -portion to raised lugs 29, on the end plate -in Fig. 1, which extends 4, a slide or movable "electricl terminal 30 and a link 31, connectingthe lever 28 to yis correspondingly raised which rocks the walking beam lever 28, and by means of the link 31, shifts the terminal slide 30 ksufficiently to separate the electric terminals and thus break the electric circuit and stop the motor.

The terminal slide 30 is mounted on the inner end of a rock shaft 34, which is journaled in a recess formed in the handle 3, and a lateral arm 35 extends from said rock shaft 34 through a .transverse slot-26, in said handle and has-a projecting knob 37 on its projecting end which is adapted to be manually manipulated to open and close the electric circuit andthus start and stop the motor. A suitable electric wire 38 is shown from any desirable source of power and is connected to a fixed electric Aterminal 39 within the housing.

While we have illustrated and described preferred forms of construction lfor carrying our invention into effect, this is capable of a wide 'range of variation, alteration, modification and change without departing from the scope of the claims, we therefore do not wish to be limited to the construction hereinshown and described, but desire to avail ourselvesof all such variations, alterations, modifications and changes as fairly fall within the scope of the appended claims or may be construed to be within the scope hereof by involving the doctrine of equivaents.

What we claim as our invention and desire to secure by Letters Patent is :le

1. In a machine of the 4class described, the combination with an electric-motor and 'a tool, of a clutch interposed between the motor and tool and connecting means whereby the disengagement of the clutch will automatically stop the motor, comprising a connecting rod, a leyeripivoted to the 4connecting rod, and a movable terminal in the motor circuit Alinked to thev lever.

2. In a machine of the class described, the combination with a motor and a tool, of a clutch interposed between the motor and tool and having a movable member adapted to disengage itself upon the applicationof abnormal strain upon the which said movable clutchY member slides said sleeve and clutch member having recesses which together form a chamber, and a clutch tensioning spring in said chamber.

3. In a machine of the class described, the

tool, a sleeve 1"n tor and-tool and having a movable member adapted to disengage itself upon the applica- .tionof abnormal strain upon the tool, and a motor circuit breaking mechanism including a svvitchya lever controlling said switch and a rod connected to the lever and having a lateral pin projecting into connection with the clutch member.

In testimony whereof We aiiXed our signatures. i n

LQQGUSTAV F. HOCHRIEM. LUDWIG E. HOCHRIEM. 

